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Systematic Reviews in the Health Sciences

A guide to systematic and other types of reviews in the health sciences. Also describes the types of support available to systematic review teams through the Health Sciences Library

Should you consider another type of review?

Not all reviews are, or should be, systematic reviews. The following article offers a typology of different review types you may want to consider (see Table 1 for brief descriptions):

Grant M, Booth A. A typology of reviews: an analysis of 14 review types and associated methodologies. Health Information & Libraries Journal. 2009;26(2):91-108.

Some alternatives you might want to consider, depending on your time, scope, and resources, include:

Systematic Search and Review / Systematized Review

See the Grant and Booth article above for full description. These tend to fall short of full systematic review. There may or may not be a fully comprehensive search, and the review may take a narrative rather than a quality assessment approach. Often these are done as course assignments, where the reviewers lack the time and resources to do a full systematic review.


Rapid Review

Purpose: To utilize the methods of systematic reviewing in a shorter timeframe to generate an immediate answer to an urgent or emerging topic. Rapid reviews make take three weeks to six months, as opposed to 18 months and up for a rigorous systematic review. They tend to be restricted to more easily-retrievable evidence; as a result, they sacrifice some of the rigour of a full systematic review.

How to do it:

Example: Hersi M, Stevens A, Quach P, Hamel C, Thavorn K, Garritty C et al. Effectiveness of Personal Protective Equipment for Healthcare Workers Caring for Patients with Filovirus Disease: A Rapid Review. PLOS ONE. 2015;10(10):e0140290. 


Scoping Review

Purpose: To assess the size and scope of available research literature, and identify gaps and research needs. The extent of the literature search depends on the reviewers time/scope constraints. While the quality of existing evidence may be described, there is usually not a formal quality appraisal process as with a systematic review.

How to do it: 

Example: Shommu N, Ahmed S, Rumana N, Barron G, McBrien K, Turin T. What is the scope of improving immigrant and ethnic minority healthcare using community navigators: A systematic scoping review. International Journal for Equity in Health. 2016;15(1).


Umbrella Review (Review of Reviews)

Purpose: To synthesize the findings of several reviews around the same question. Quality appraisal may be of the reviews themselves, or of the studies contained within them.

How to do it: 

Example: Lau R, Stevenson F, Ong B, Dziedzic K, Treweek S, Eldridge S et al. Achieving change in primary care—effectiveness of strategies for improving implementation of complex interventions: systematic review of reviews. BMJ Open. 2015;5(12):e009993.


Realist Review 

Purpose: To situate the evidence in the context in which it is being applied - realizes that context influences the outcomes of an intervention. Often summed up as "what works, how, for whom, in what circumstances and to what extent?" (Greenhalgh et al., 2011).

How to do it:

Example:

Smylie J, Kirst M, McShane K, Firestone M, Wolfe S, O'Campo P. Understanding the role of Indigenous community participation in Indigenous prenatal and infant-toddler health promotion programs in Canada: A realist review. Social Science & Medicine. 2016;150:128-143.